The overall objective is to investigate the early stages of glucose utilization in yeast and animal tissues. The specific aims are: (1) to study further the yeast hexokinases P-I and P-II and to initiate studies on glucokinase, especially with respect to (a) regulation of their activity by phosphorylation, (b) their location in the yeast cell and (c) the regulation of the synthesis of form P-I; (2) to study glucose transport in animal cells, especially with respect to (a) our recent finding of stimulatory effects of Epidermal Growth Factor and of various particulates, including calcium phosphate on cultured fibroblasts and (b) the recently discovered suppressing effect of adenosine; (3) to investigate carbohydrate metabolism in muscular dystrophy, especially with respect to (a) the nature of the reported defect of type II hexokinase in Duchenne muscular dystrophy, and (b) the glucose uptake and growth of cultured fibroblasts from such patients.